Overhead valve engine



Oct. 25, .1960

Original Filed Jan. 4. 1955 M.. L. CARPENTIER ET AL MEL BOUENE L.CAPPF/V T/EE, 011354.751)

PAUL/NE I' CO-ADMINISTRATOES,

GEE/1Z0 KANE WILLIAM E. Dew/(A20 MMM jrrax/vzrsi Oct. 25, 1960 M. L.CARPENTIER ETAL 2,957,451

OVERHEAD VALVE ENGINE! 5 Sheets-Sheet 2 Original Filed Jan. 4. 1955 D/ IM; m m m 0 z N e ww x wwz a w w 0 W u. r N 5 m 7 5 /@W]E L 5m? w: w u O5 U m 9 M 5 Oct. 25, 1960 M. L. CARPENTIER ETAL 2,957,461

OVERHEAD VALVE ENGINE Original Filed Jan. 4. 1955 5 Sheets-Sheet 3INVENTOES MEL BOUENE 1.. CAE'PE/VT/EE, 05([4 $50, 5) PAUL/NE LUOM?CU-ADM/N/STQATOIES/ W/LL/AM E. DRINK/12D FZTOFNF/Q Oct. 25, 1960 M. L.CARPENTIER ETI'AL ,4

OVERHEAD VALVE ENGINE Original Filed Jan. 4. 1955 v 5 Sheets-She et 5//v VENTOES MELBOURNE L, cAepE/vT/EQ, DECEASED,

2223 b g 2 co-Ao/nw/sreAraes W/LL/AM E DEM/K420 United States PatentO2,957,461 OVERHEAD VALVE ENGINE Melbourne L. Carpentier, deceased, lateof Detroit, Mich., by Pauline Luoma, Royal Oak, and Gerald Kane, GrossePointe, Mich., coadministrators, and William E. Drinkard, Birmingham,Mich., assignors t Chrysler Corporation, Highland Park, Mich., acorporation of Delaware 1 v Original application Jan. 4, 1955, Ser. No.479,756,

now Patent No. 2,833,254, dated May 6, 1958. Divided and thisapplication Oct. 2, 1957, Ser. No. 687,830

11 Claims. (Cl. 123'-55) This invention relates to internal combustionengines of the overhead valve type and particularly to V engines of thischaracter. The subject application is a division of our copendingapplication Serial No. 479,756, filed January 4, 1955, now Patent No.2,833,254.

More especially our invention rel-ates to improvements in. certainaspects of passenger car engines such as disclosed in United StatesPatent No. 2,669,227, granted February 16, 1954, to William E. Drinkard.This patent shows and claims among other features, constructions whichcombine in a passenger car engine a hemispherical combustion chamberhaving a particular arrangement of intake and exhaust valves and firingelement, facilitating high power outputsyet avoiding the roughness andcomplex mechanical arrangements found in aircraft andracing applicationswhere hemispherical combustion chambelrs have sometimes foundapplication and which arrangement renders the engine practical forpassenger car operation. It is the purpose of the present invention,among other things, to retain to the greatest degree the advantages ofthe Drinkard combination while at the same time attaining a newcombination having in addition to other novel features a more compactand lighter weightengine construction.

We have discovered that by providing the valve drive mechanism with asingle rocker shaft for the valve operating arms instead of a doublerocker shaft arrange ment asin Dninkard, and positioning the intake andexhaust valves and sparking element in a particular relationship, acombination having the desired compactness of structure and weightreduction is attainable while at the same time providing a combustionchamber-having the high thermal and volumetric eificiency and powercharacteristics of the hemispherical chamber of Drinkard as well as amore accessible positioning of the firing element and other parts forservicing and for their protectio'Ii.

It is therefore the principal object of the present inv'e'ntion toprovide an engine retaining as much as pos-' sible of the features of apure hemispherical combustion chamber and valve arrangement of theDrinkardengines but providing an engine construction that is morecompact and of lighter weight and in which the valve operating mechanismand ignition elements are more readily accessible for servicing.

A further object of this invention is to provide an engine having thefeatures of the preceding object and wherein the inlet and exhaustvalves animated and seatfiring elements of the combustion chambers areaccessible ice from the exhaust side of the engine and at positionsdisplaced from the valve operating mechanism making each accessibleindependently of the other.

A specific object is to provide an arrangement as in the precedingobject wherein the firing elements are protected from road splash by theexhaust manifolds.

Still another object is to provide an engine as inany of the precedingobjects having direct free flowing intake and exhaust ports andpassages, large valves widespread to facilitate circulation of coolingwater around the ports and eliminate hot spots, a low surface area tovolume ratio, a smooth angle of entry for the incoming fuelair mixtureavoiding scrubbing against hot deposits, if any, a short flame travel toavoid detonation, minimum susceptibility to preignition, ability toadjust for a wide range of compression ratios and ability to operate anordinary low fuel octane.

A more particular object of this invention is to provide an engine as inthe preceding objects having a compact valve operating mechanismfeaturing a single rocker shaft for all the inlet and exhaust valveoperating arms of a bank; having combustion chambers of planosphericalcharacter possessing the desirable characteristics of pure hemisphericalchambers; having a single inlet valve and a single exhaust valve foreach cylinder of the engine substantially free of close walls of thevalve passages and whose ports in the combustion chamber are on oppositesides of a longitudinal axis through the cylinders .of a bank of theengine and staggered lengthwise thereof, and whose passages connectingwith the ports are relatively short and transversely directed; andhaving a spanking element for each cylinder positioned in the cylinderhead at the; exhaust valve side of the engine and laterally andexteriorly of the valve operating mechanism and inboard of the exhaustmanifold so as to be protected thereby and whose firing points aregenerally directed toward the central-region of the combustion chamberat a position intermediate the intake and exhaust valve ports thereof.

Another particular object is the provision of an engine such a in thepreceding objects wherein the intake port of each combustion chamberwhen viewed from the end of the engine, has its axis substantiallyoblique or inclined to the vertical axis of the cylinder it feeds and toa vertical plane containing this cylinder axis and all others of thesame bank and which extended and translated intersects the axis of thiscylinder at a point below the center of curvature of the hemisphericalsurface portion of the combustion chamber; wherein the exhaust valveport has its axis in the intersection of two planes, one a planeparalleling said vertical plane through the cylinder axes and on theopposite side thereof from said intake port and the other a plane normalto said vertical plane,

'andwhereinthe intake and exhaust ports are within the combustionchamber and have the widest possible spacmg.

A further particular object is to provide an engine as in the precedingobjects wherein the axis of each intake valve is angularly inclined withrespect to the vertical axis of the cylinder and combustion chamber inwhich it operates and is contained in a-transverse plane normal toalongitudinal plane containing the axes of the cylinders of the samebank containing this cylinder, which transverse plane parallels a secondtransverse plane through the vertical axis of this cylinder and normalto said longitudinal plane and wherein each exhaust valve axis issubstantially parallel to the axis of its cylinder and on opposite sidesof the said longitudinal and transverse planes through this cylinderaxis from the intake valve axis and is defined by the intersection ofvertical planes paralleling said longitudinal and normal planes throughthe cylinder axis; and wherein the firing element is oriented in aposition at an angle to' of said longitudinal and normal planes throughthe axis of the cylinder.

Another particular object is to provide an engine as in the precedingobjects having a valve operating mechanism in which the opposite leverarms of each of the inlet and exhaust valve rocker arms bear asubstantially similar numerical ratio to each other and wherein thesimilarly functioning levers of these arms are of substantially the samelength, whereby to facilitate equalization of wear of the camshaftportions actuating the push rods for such rocker arms and to facilitateequalization of spring loads on the inlet and exhaust valves.

A further particular object is to provide an engine as in the precedingobjects in which the spark plug for each combustion chamber is disposedin a shallow cavity in the cylinder head adjacent the exhaust side ofthe engine, exteriorly of the rocker arm mechanism arm cover and inboardof the exhaust manifold so as to make the spark plug readily accessiblewithout special tools and protected from road splash and to make therocker arm mechanism accessible without disturbing the spark plugs, thespark plug cavity being so directed as to enable positioning of thesparking elements thereof in the central zone of the combustion chamberin which the plug operates.

Further objects and advantages of my invention will be more apparent asthis description proceeds, reference being had to the accompanyingdrawings in which:

Figure l is an end elevational view partly in section of a V engineembodying the novel features of our invention;

Figure 2 is a plan view of a portion of the cylinder head and rocker armmechanism of one of the engine banks of Figure l, a portion of therocker arm cover being cut away to show the rocker arm mechanism;

Figure 3 is a sectional elevational view taken approximately on the line3-3 of Figure 2 parts being broken away to show the intake valve portand passage in section;

Figure 4 is a plan view looking upwardly into the combustion chamber ofthe engine structure of Figure 3 in the direction of the arrows 4-4 inthat figure and showing the relationship of the valves and sparkingelement of one of the cylinders of the engine;

Figure 5 is a sectional view taken at 55 of Figure 4;

Figure 6 is a sectional view taken at 6-6 of Figure 4;

Figure 7 is a plan view taken similarly to that in Figure 2 and showinga modified form of rocker arm mechanism structure and spark plug cavity,portfons of the rocker cover being broken away to expose the rockermechanism and cover mounting face;

Figure 8 is a sectional elevational view of an engine embodying themechanism of Figure 7 and showing the valves and valve operatingmechanism of Figure 7, this section being taken approximately along theline 8-8 of Figure 7, parts being broken away to show the intake valveport and passage in section;

Figure 9 is a plan view looking upwardly into the combustion chamber ofthe engine in Figure 8 in the direction of the arrows 9-9 and showingthe positioning of the valves and sparking element in relation to thecavity formed in the spherical surface of the combustion chamber;

Figure 10 is a sectional elevational view taken at approximately 1010 ofFigure 7 and 1010 of Figure 9 showing the manner of mounting the sparkplug in the combustion chamber of the engine of Figure 7 in relation tothe spherical surface and valves of that chamber;

Figure 11 is a sectional elevation of the combustion chamber of theengine of Figure 8 taken at approximately 11-11 of Figure 9; and

Figure 12 is another sectional elevational view of the combustionchamber of the engine of Figure 8 taken approximately at 12-12 of Figure9.

For the purpose of illustration but not restriction, our invention willbe described relative to two forms of V-8 engines, one of currentmanufacture, which engines are provided with so-called two-plane 90crankshafts, modified spherical combustion chambers, and downdraftcarburetion of the dual type, the risers of which are preferablyarranged to feed a pair of inner cylinders of one bank and a pair ofouter or end cylinders of the opposite bank. It will be understood,however, that our invention is also applicable to line engines, toengines of any number of cylinders, and in conjunction with any form ofcarburetion or fuel injection.

As seen in Figure l, the V engine there illustrated has two cylinderbanks 9 and 9a of cylinders 10, a plurality, for example 4 in each. bankarranged at 90 in a cylinder block 11 to which interchangeable cylinderheads 12 and 12a are secured in the customary manner by bolts not shown,and which heads are provided with combustion chambers 13 immediatelyabove each cylinder 10. Although only one cylinder is illustrated inFigure 2, it will be understood that the cylinders of each bank arealigned longitudinally of an axis 14 paralleling the longitudinal axis(not shown) of the engine and that the cylinders of the opposite banksare offset longitudinally relative to each other as is conventional in Vengine practice.

Each cyl'nder 10 is provided with a piston 15 reciprocable therein andoperably connected to the crankshaft 16 through a connecting rod 17 andwrist pin 18.

The form of the combustion chamber 13, arrangement of valves and theiroperating mechanism and of the spark providing element are importantfeatures of our invention.

Thus we have provided, as seen for example in Figures 1, 3, 4, 5, 6, 8,9, and 10, a cylinder head combustion cavity 13 of dome-like characterdirectly opposite the upper end of the cylinder bore 10 and defined by aspherical wall or surface 21 which rises from and returns to a generallycircular perimeter 22 overlying the cylinder bore 10 and which is in aplane 22A containing the mounting face of the cylinder head. Thisspherical surface, as evident from the drawings, is interrupted by oneor more cavities in the region of the valves and sparking element,Figures 3 and 4, illustrating an arrangement wherein the sphericalsurface 14 has been machined and is interrupted by machined cavities23a, 23b, for the exhaust valve and sparking element respectively, andFigures 8 and 9 illustrating an arrangement wherein the chamber 13 iscast and the spherical surface is interrupted by an outward cavity ofpolygonal configuration generally referred to by the numeral 24 anddescribed in greater detail, formed in the spherical surface 21 in thearea of the valves and firing element.

Referring now more particularly to the valve arrangement and itsoperating mechanism, it will be observed that each combustion chamber 13is provided with a single inlet valve 25 and a single exhaust valve 26and e that in contrast to the Drinkard patent disclosure aforesaid,where these valves are located on a great circle through the transverseaxis 28 of the cylinder and chamber, the valves of the present inventionwhile still generally transversely directed in the sense that they areon opposite sides of the longitudinal axis 14 of the cylinder bank havealso been oriented to positions on opposite sides of the transverse axis28. More specifically, as seen in Figures 4 and 9, the inlet valve 25 ispreferably positioned only slightly to one side (below in Figures 4 and7) of the transverse axis 28 and to the left of the longitudinal axis14. While the exhaust valve is positioned a substantial distance abovethe transverse axis 28 and to the right of the longitudinal axis 14,such that the two valves transversely speaking as seen in Figures 4 and9, are quite close to each other yet the distance between their centersat the ports 25a and 26a respectively, which they close, aresubstantially that possible in the Drinkard patent arrangement.

This arrangement makes possible the use of large inlet valves and thusfacilitates the admission of a maximum quantity of air to the combustionchambers with resultant high thermal efficiency. Moreover, it is stillpossible for the axis 29 of the intake valve 25 toextend as teloselyzaspossible in the direction of flow of the fuel air mixture in thetransversely extending inlet'passage 30 leading to the intake port 25ato thereby avoid making the fuel air mixture move around sharp .or shortbends on entering the chamber 13. Moreover, it is still possible toprovide short transversely extending exhaust passages 31.

For the purpose of illustration but not limitation, it may be said thatin one construction as in Figures 8 and 9 where the cylinder had a 3 /2"diameter bore, the center of the inlet valve 25' projected to the planeof Figures 4 and 9 was located about Ms from the center of the cylinder10 on a radial line therefrom forming an angle or of about 8 with thetransverse axis 28, and the axis of the exhaust valve 26 projected tothe same planes was located about 1" from the center of the cylinder ona radial line forming an anglefi about 135 with the radial line locatingthe intake valve. Moreover, as, will be further evident from Figures 3,'4, 8, and 9 the valves are not only oriented as described above, butthe axis 32'of the exhaust valve is substantially vertical andsubstantially parallel to the vertical axis 33 of thecylinder andcombustion chamber, while the intake valve axis 29 is inclined to thevertical axis 33 of the cylinder. In the case of the engine constructionexemplified above having a 3 /2" bore, the angle between the axes 29 and33 measured in the plane of Figures 3 and 8, was substantially about 22/2 and the axes 29, 33 intersected in the plane of Figure 3 about 1below the mounting face plane 22A.

The aforesaid particular location and positioning of the intake andexhaust valves facilitates operation'of the valves from rocker armshaving a common axis of oscillation and having relatively short leverarms of similar leverage or ratio while at the same time retaining thenovel feature of operation of both valves from a single camshaft 36located as high as possible above the crankshaft 16 as seen in Figure 1.

The described arrangement moreover facilitates a substantial compactingof the valve operating mechanism making possible narrow and moreaccessible rocker mechanism covers 37, 38 (Figures 3, 8) and enablespositioning of the spark plug 39 at a position at the exhaust side ofthe engine and removed from the valve mechanism where it is accessiblewithout the use of special tools, and such is possible withoutsacrificing the advantageous location of the sparking elements 40, 41 ofthe plug 38 intermediate the intake and exhaust valves and generallycentrally of the combustionchamber as will be evident from Figures 4 and9 and as hereinafter described.

The inlet valves 25 and their ports 25a are served by transverselyextending passages 30 of the cylinder heads which in turn connect withintake passages 42 of the intake manifold 43 (see Figure 1) the passages42'being fed from the carburetor risers (not shown). Moreover, theexhaust valves 26 and their ports 26a are associated with thetransversely extending exhaust passages 31 in :the cylinder heads andconnect with the exhaust manifold 44 which protects the spark plug wells45 from road splash.

Referring now to Figures 1, 2, 3, 4, 5, and 6, it will be evident thatin the embodiment in these figures the intake valve 25 closing the port250 operates directly against a seat 46 formed in the spherical surface21 of'the combustion chamber 13, while the exhaust valve 26enclosing-the port 26a operates against a seat 48 provided on a hardenedheat-resistant ring insert 50 mounted in a shouldered recess or cavity23a machined in the spherical surface 21.

Moreover, the stems 52, 54- of the intake and exhaust valvesrespectively are slidably journalled inb-ushings 56, 58 respectivelymounted in the cylinder heads 12 and 12a. Fixed to the upper ends 60, 62of the valve stems are split collars 63 beneath which are doubleconcentric compression springs 64, 65 serving to normally maintain thesevalves in closed position.

The valves 25, '26 of the Figure '3 arrangement are 01)- erated as seenin Figures 1, 2, and 3 by the camshaft 36 through suitable tappet andpush rod mechanism. Thus conventional tappets 67 may be associated withthe camshaft 36 and are slidably journalled in lateral bearing portions68 integral with the cylinder block 11. These tappets are operablyconnected through suitable push rods '70, 71 with the relatively shortlever portions 72, 73 respectively of the inlet valve and exhaust valverocker arms generally referred to by the numerals 74, 75 respectively,which arms are journalled on a common stationary rocker shaft 76 carriedin bearing blocks or brackets 77 bolted to the top side of the cylinderheads 12 and 12a. By thus separately attaching the rocker shaft to thecylinder head the entire rocker assembly can be removed for inspectionor repair without loosening the cylinder head from the block.

It will be noted that the push rods 78, 71 respectively communicate withadjustable ball-headed pins 78 secured to the short lever portions 72,73 of the rocker arms 74, 75 respectively, while the long lever portions79, 80 of these rocker arms communicate with the shank ends 60, 62respectively, of the valves. The pins 78 operate in spherical recesses81 in the ends of the push rods and are retained in their adjustedposition on the rocker arms by locking nuts 82.

By reason of our novel valve arrangement, it is found possible to makethe lever ratio of the short levers 72, 73 to the long levers 79, 80 ofthe rocker arms 74, 75 of the same numerical value such that there maybe substantially equal wear on the cam surfaces 83 of the camshaft 36.Preferably, the corresponding short levers 72, 73 respectively of theinlet and exhaust valve rockers 74, 75 will be of the same length andthe same will preferably be true of the long levers 79, 80.

It will be seen from Figure 2 that the bearing blocks 77 straddle eachcylinder so as to confine the rockers 74, 75 between them. As seen, theopposite lever portions of each of the rocker arms are offsetlongitudinally of the engine so as to facilitate connection thereof withthe push rods and valve shanks, the amount of offset being considerablygreater in the case of the intake rocker arm 74. Each of the inlet andexhaust rocker arms 74, 75 respectively, are provided with hub portions84, 85 respectively, which rotatably mount them upon the rocker shaft 76and these arms are held in their longitudinal locations against thebearing blocks 77 by a compression spring 86. As will be evident fromFigures 2 and 3, the push rods 70 and 72 extend through suitableclearance openings 87, 88 in the cylinder heads which are located asclose as possible to the cylinder bore 10 and are on opposite sides ofthe intake valve passage 30.

Covering the valve operating mechanism of Figures 2 and 3 is a dishedcover 37 which may be secured by bolts 89 threaded into the bearingblocks 77 as at 90, this cover 37 being sealed against the top face 91of the cylinder head by a resilient gasket 92 acting between aperipheral flange .93 of the cover 37 and the top face 91 of thecylinder head.

Alternatively (see Figure 1) the cover 37 may be held in place by acornnuts 92 acting against shouldered collars 93 slipped over studs 94rigidly carried by the hearing blocks 77 to which they are locked bynuts 95.

As seen in Figure 2, the exhaust side of the rocker mechanism cover 37has its flange portion 93a and side wall portion 96 provided withalternate bulges 97 and valleys 98 (only one of each being shown) toprovide in effect a scalloped edge. The cylinder heads 12 and 12a arerecessed adjacent the valleys by angularly inclined cylindrical bores45which extend inwardly of the cylinder heads in the direction of thecentral region of the combustion chambers 13 and terminate incylindrical threaded apertures 102 in which the sparking elements 39 aremounted and through which they extend into the recesses 23b of thecombustion chambers. As evident from Figures 1, 2 and 3, it will beobserved that the axes of the bores 45 and elements 39 are inclined to avertical longitudinal plane and to a transverse vertical plane. The sameinclination is evident in Figures 7, 8 and 10. In the exemplifiedstructure described above having a 3 /2" bore, the axis of the sparkingelement 39 was arranged at an angle of about 18 to the verticallongitudinal plane through the cylinder axis 33 measured in the plane ofFigures 3, 8, and at an angle of about 24 to the transverse verticalplane measured in the plane of Figures 2 and 7 and extended from a pointof origin distant from the vertical longitudinal plane from thetransverse vertical plane and 1%.," above the mounting face 22A.

It will be observed that by reason of the compact construction andarrangement of the valve mechanism, it is possible to make the sparkelements 39 not only accessible from the exhaust side of the engine andindependently of the rocker arm cover 37, but that no special tools willbe required for removing and replacing the sparking elements and thatthey are advantageously exposed in the combustion chamber 13 at aposition intermediate the intake and exhaust valves and generallycentrally of the chamber.

In Figures 8 to 12 the construction is of somewhat simplified form, thecombustion chamber 13 in these figures being of modified spherical formadapted for casting to its finished dimensions and shape. Here theintake valve 25 operates directly against a seat 110 formed on a flatcast face 112 which is normal to the intake valve axis 29 and comprisedin the outward polygonal depression generally designated by the numeral24, of the spherical surface 21 basically defining the combustionchamber while the exhaust valve operates directly against a seat 116formed in a fiat cast face 118 also comprised in the polygonaldepression 24 and which face 118 is in a plane generally normal to theaxis 32 of the exhaust valve 26 and slightly above and paralleling atangential plane to the dome of the basic spherical surface.Intermediate the intake and exhaust valve ports 25a and 26a and betweenthe cast faces 112, 118 mounting the valves 25, 26 are flat triangularcast surfaces 120, 1'22 providing a stepped relation with the faces 112,118, as seen for example in Figures 11 and 12, and the apexes of whichtriangular surfaces meet approximately on a line connecting the centersof the valve ports. The triangular face 120 moreover terminates at itsouter end in the spherical surface 21 while the triangular face or land122 terminates at its end adjacent the spherical surface 21 in a conicaldepression 124, best seen in Figure 10, through which the firingelements 40, 41 of the spark element or plug 39 may project.

The stems 52, 54 of the intake and exhaust valves of Figure 8 areslidably journalled directly in suitable bores provided in the cylinderheads 12 and 12a thus omitting the bushings of the Figure 3construction. Fixed to the upper ends 60, 62 of the valve stems in thisfigure are split collars 126 beneath which are single compressionsprings 128 serving to normally maintain these valves in closedposition. The valves in Figure 6 are operated as those of Figure 3 bythe camshaft 36 of Figure 1 through suitable tappet and push rodarrangements. Thus conventional tappets 67 may be associated with thecamshaft 36 and are slidably journalled in the lateral bearing portions68 integral with the cylinder block 11. These tappets are operablyconnected through suitable push rods 130, 132 with the relatively shortlever arms 134, 136 respectively of inlet valve and exhaust valve rockerarms 74a, 75a respectively, which are journalled on a common hollowrocker shaft 138 carried in mounting blocks 140 secured by bolts 142 tothe top face of the cylinder heads 12 and 12a.

It will be noted that the push rods 130, 132 have ball-ended tips 144which are received in spherical sockets 146 of the short lever portions134, 136 of the rocker arms while the long lever portions 148, 150 ofthese rocker arms abut against the ends of the shanks 52, 54respectively of the valves. As in the case of the Figure 3 arrangement,our novel structure and valve arrangement facilitates the use of rockerarms for both intake and exhaust valves, the ratios of whose short tolong lever arms the same, thus making possible equal wear on the camfaces 83 of the camshaft 36. Moreover, by preference, the correspondingshort levers 134, 136 respectively, of the intake and exhaust rockerarms will be of the same length and the same will be true of thecorresponding long levers 148, 150.

As seen in Figures 1, 8, and 10, the valve operating mechanism of Figure8 is covered by a narrow dished cover 38 having a downwardly edge bentflange 152 seated on a raised ledge 154 of the heads 12 and 12a. Theportion 152a of the flange at the exhaust side of the engine isscalloped as seen in Figure 7 and the portion 154 of the ledge uponwhich it seats is similarly contoured. The flange portion opposite theportion 152a as well as the end flanges are substantially straight andseat on straight portions of the cylinder head projection 154. The cover38 is mounted on the cylinder heads through an intervening resilientgasket which is confined between side wall portions 162, 163 of thecover flanges. It will be noted from Figures 7 and 8 that certain of therocker shaft bearings 164 mounting bolts 165, to wit, the mounting bolts94 as in Figures 1 and 8 are in the form of studs described aboveprovided with upward stud extensions which project through openings 166in the cover 38 and over which are received shouldered collars 93 andacorn-shaped nuts 92 for securing the cover in place, the collars havingtheir reduced portions received in the openings 166.

It will be noted from Figures 8 and 10 that in the region between theoutward bulges 176 of the scalloped portions of the cover flange 152aand cylinder head ledge 154a, the cylinder head casting drops to a lowerlevel 180 where it provides a cylindrical stepped bore 182 for receivingthe spark element 39, this bore 182 opening into the conical depression124 of the combustion chamber and its lowest step 184 being threaded tomount the spark element 39. It will be evident that the sparking element39 in Figures 8 and 10 is more readily accessible than that in theFigure 3 construction. As in Figure 3, the sparking element 39 is herealso spaced from the valve operating mechanism and cover and itssparking points 40, 41 project into the combustion chamber at a positionintermediate the intake and exhaust valves and generally centrally ofthe chamber.

A further feature of our invention is the mode of carrying oil to theupper push rod tips and to the intake valves. Thus oil under suitablepressure is carried to the hollow rocker shaft 138, which may besuitably plugged at its opposite ends. The oil is conducted here throughholes (not shown) in the camshaft journal and drilled passages (notshown) in the block and cylinder heads to holes 180 in the rocker shaftbracket studs 94. Holes 182, 184 through the walls of the hollow rockershafts 138 meter oil to passages 186, 188 in the rocker arms connectingthrough their bores with the holes 182, 184 respectively, and thus oilis conducted by gravity via passages 190, 192 to the push rod sockets144 for lubricating the push rod tips. The passages 186, 138 indexperiodically with the holes 182, 184 of the rocker shaft to receivefresh oil. The intake valve stems are lubricated through a hole orpassage 194 in the intake valve rocker arm 74a which does not registerwith a hole in the rocker shaft 138 but which merely picks up oilseeping around the bearing. This is done as a precaution againstover-oiling.

Although our invention has been particularly illustrated as applied tospecific V engine applications, it will be understood that theprinciples and features disclosed may be applied by those skilled in theart to other engines and that various changes, modifications and saidcommon plane and substitutions may be made without departing from thespirit and intent of our invention.

plane, a cylinder head on said block having a mounting surface inassembled relation to saidblock, a combustion chamber over each cylinderbore, a single inlet valve and a single exhaust valve disposed in eachchamber, the axis of said inlet valve being on one side of said commonplane and lying in a transverse plane which is normal to said commonplane, and on one side of and in juxtaposition to a second transverseplane normal to said common plane and through the vertical axis of itscylinder bore, and said inlet valve axis being inclined to said commonplane at an acute angle and intersecting said plane at a point belowsaid mounting surface and the axis of said exhaust valve substantiallyparalleling said cylinder bore axis andybeing .ofiset from said commonplane and said second transverse plane and on opposite sides of each ofthese planes from said inlet valve axis, an operating lever arm for saidinlet valve having its axis of oscillation extending longitudinally ofthe engine and located above and intermediate said valves and on theinlet valve side of said common plane,

an operating lever arm for said exhaust valve having its axis ofoscillation substantially coaxial with that of said inlet valveoperating arm, each of said operating arms having opposite leverportions one of greater length than the other, crankshaft means carriedby said block, valve operating cam means carried by said block andextending longitudinally of said engine above said crankshaft means andto one side of said cylinder head, push rod rmeans operably connectingsaid cam means with the shorter of said levers of each valve operatingarmand stem means on each valve operably connecting with the longer ofsaid levers of its operating arm.

2. An internal combustion engine comprising a cylinder block, aplurality of cylinder bores arranged therein longitudinally of theengine with their axes 'in a common plane, a cylinder head on said blockhaving'a mounting surface in assembled-relation to'said block, acombustion chamber over each cylinder bore, a single inlet valve and asingle exhaust valve disposed in each chamber, the axis of said inletvalve being on one side of said common plane and lying in atransverse-plane which is normal to said common plane and on one side ofand in'juxtaposition to a second transverse plane normal to through-thevertical axis of its cylinder bore, and said inlet valve axis beinginclined to said common plane at an acute angle and intersecting saidcommon plane at apoint below said mounting-surface and the axis of saidexhaust valve substantially paralleling said cylinder bore axis andbeing offset from said common plane and said second transverse plane andon opposite sides of each of .these planes from said inlet valve axis,an operating lever arm for said inlet valve having its axis ofoscillation extending longitudinally of the engine and located above andintermediate said valves and on the inlet valve side of saidcommonplane, an operating lever arm for said exhaust valve having itsaxis of oscillation substantially coaxial with that of said inlet valveoperatingarm, each of said operating arms having opposite lever portionsone of greater length than the other, crankshaft means carried by saidblock, valve operating cam means carried by said block and extendinglongitudinally of said engine above said crankshaft means and to oneside of said cylinder head, push rod means operably connecting said cammeans withrthe shorter of said levers of each valve operating arm andstem means on each valve operably connecting with'the longer of saidlevers of its operating arm, the ratio of the longer to theshorter ofthe'levers of each said valve operating arms being substantially thesame.

'3. An internal combustionengine comprising a cylinder block, aplurality of cylinder bores arranged therein longitudinally of theengine with their axes in a common plane, a cylinder head on said blockhaving a mounting surface in assembled relation to said block, acombustion chamber over each cylinder bore, a single inlet valve and asingle exhaust valve disposed in each chamher, the axis of said inletvalve being on one side of said common plane and lying in a transverseplane which is normal to said common plane, and on one side of and injuxtaposition to a second transverse plane normal to said common planeand through the vertical axis of its cylinder bore, and said inlet valveaxis being inclined to said common plane at an acute angle andintersecting said common plane at a point below said mounting surfaceand the axis of said exhaust valve substantially paralleling saidcylinder bore axis and being offset from said common plane and saidsecond transverse plane and on opposite sides of each of theseplanesfrom said inlet valve axis, an operating lever arm for said inletvalve having its axis of oscillation extending longitudinally of theengine and located above and intermediate said valves and on the inletvalve side of said common plane, an operating lever arm for said exhaustvalve having its axis of oscillation substantially coaxial with that ofsaid inlet valve operating arm, each of said operating arms havingopposite lever portions one of greater length than the other, crankshaftmeans carried by said block, valve operating cam means carried by saidblock and extend-- ing longitudinally of said engine above saidcrankshaft means and to one side of said cylinderhead, push rod meansoperably connecting said cam means with the shorter of said levers ofeach valve operating arm .and sternmeans on each valveoperablyconnecting withthe longer of said levers of its operating arm,add the levers of said valve operating arms operable by said push rodsbeing of substantially thes-ame length and all of the levers of saidvalve operating iarms acting on said valve stems being of substantiallythe same length.

4. An internal combustion engine comprising a cylinder block, aplurality of cylinder bores arranged therein longitudinally of theengine With their axes in a common plane, a cylinder head on said blockhaving a mounting surface in assembled relation to said block, acombustion chamber over each cylinder bore, a single inlet valve and asingle exhaust valve disposed in each chamber, the axis of said inletvalvebeing on one side of said common plane and lying in a transverseplane which is normal to said common plane, and on one side of and injuxtaposition to a second transverse plane normal to said common planeand through the'vertical axis of its cylinder bore, and said inlet valveaxis being inclined to said common plane at an acute angle andintersecting said common plane at a point below said mounting surfaceand the axis of said exhaust valve substantially paralleling saidcylinder bore axis and being offset from said common plane and saidsecond transverse plane and on opposite sides of each of these planesfrom said inlet valve axis, an operating lever rocker arm for each ofsaid inlet valves and an operating lever rocker arm for each of saidexhaust valves, all carried by a single rocker arm shaft extendinglongitudinally of the engine, and above and intermediate said valves andon the inlet valve side of said common plane, each of said rocker armshaving opposite lever portions one of which is operable to act on avalve, crankshaft means carried by said block and extendinglongitudinally of the engine, valve operating cam means carried by saidblock and extending longitudinally of said engine above said crankshaftmeans and push rod means operably connecting said cam means with thelever arms of said rocker arms opposite those acting on said valves.

5. An internal combustion engine comprising a cylinder block, aplurality of cylinder bores arranged therein longitudinally of theengine with their axes in a common plane, a cylinder head on said blockhaving a mounting surface in assembled relation to said block, acombustion chamber over each cylinder bore, a single inlet valve and asingle exhaust valve disposed in each chamber, the axis of said inletvalve being on one side of said common plane and lying in a transverseplane which is normal to said common plane, and on one side 'of and injuxtaposition to a second transverse plane normal to said common planeand through the vertical axis of its cylinder bore, and said inlet valveaxis being inclined to said common plane at an acute angle andintersecting said common plane at a point below said mounting surface,and the axis of said exhaust valve substantially paralleling saidcylinder bore axis and being offset from said common plane and saidsecond transverse plane and being on the opposite side of each of theseplanes from said inlet valve axis, a sparking element extending intoeach chamber from the top side of said head on the exhaust valve sidethereof, the axis thereof being inclined to said common plane and tosaid second transverse plane and intersecting said common plane at apoint below said mounting surface but above the point where the axes ofthe inlet valves intersect this plane, an operating lever arm for saidinlet valve having its axis of oscillation extending longitudinally ofthe engine and located above and intermediate said valves and on theinlet valve side of said common plane, an operating lever arm for saidexhaust valve having its axis of oscillation substantially coaxial withthat of said inlet valve operating arm, each of said operating armshaving opposite lever portions one of greater length than the other,crankshaft means carried by said block, valve operating cam meanscarried by said block and extending longitudinally of said engine abovesaid crankshaft means, push rod means operably connecting said cam meanswith the shorter of said levers of each valve operating arm and stemmeans on each valve operably connecting with the longer of said leversof its operating arm, a dished rocker cover seated on said cylinder headtop side and extending longitudinally of the engine to cover the valveoperating mechanism, the side of said cover adjacent the exhaust valveshaving an undulated shape comprising outwardly extending portionsextending around the exhaust valve mechanism to cover the same andvalleys intermediate the outwardly extending portions for skirting saidsparking elements so as to render them visibly accessible exteriorly ofsaid cover.

6. An internal combustion engine comprising a cylinder block, aplurality of cylinder bores arranged therein longitudinally of theengine with their axes in a common plane, a cylinder head on said blockhaving a mounting surface in assembled relation to said block, acombustion chamber over each cylinder bore, a single inlet valve and asingle exhaust valve disposed in each chamber, the axis of said inletvalve being on one side of said common plane and lying in a transverseplane which is normal to said common plane, and on one side of and injuxtaposition to a second transverse plane normal to said common planeand through the vertical axis of its cylinder bore, and said inlet valveaxis being inclined to said common plane at an acute angle andintersecting said common plane at a point below said mounting surfaceand the axis of said exhaust valve substantially paralleling saidcylinder bore axis and being offset from said common plane and saidsecond transverse plane and being on the opposite side of each of theseplanes from said inlet valve axis, the top side of said head on saidexhaust valve side thereof being stepped and the inner side of said stepdefining a vertical wall of scalloped shape whose outward portionsextend around the exhaust valves and whose valleys occur between eachpair of adjacent exhaust valves, a sparking element extending inwardlyfrom the base of said step at the valley adjacent each exhaust valve andopening into the combustion chamber at a position intermediate saidvalves, the axis of said element being inclined to said common plane andto said second transverse plane, an operating lever arm for said inletvalve having its axis of oscillation extending longitudinally of theengine and located above and intermediate said valves and on the inletvalve side of said common plane, an operating lever arm for said exhaustvalve having its axis of oscillation coaxial with that of said inletvalve operating arm, each of said operating arms having opposite leverportions one of greater length than the other, crankshaft means carriedby said block, valve operating cam means carried by said block andextending longitudinally of said engine above said crankshaft means,push rod means operably connecting said cam means with the shorter ofsaid levers of each valve operating arm and stem means on each valveoperable connecting with the longer of said levers vof its operatingarm, and a dished rocker arm cover seated on the top side of saidcylinder head and having its exhaust valve side provided with a scallopconforming substantially to that of the inner side of said cylinder headstep.

7. In an internal combustion engine of the V type having a blockprovided with opposite cylinder banks each having a plurality ofcylinder bores longitudinally spaced therein, and a head on each bankhaving a plurality of combustion chambers, one for each cylinder boreand superimposed thereon, an intake and exhaust system for saidcombustion chambers of each bank comprising an intake and an exhaustport in each said chamber on opposite sides of a longitudinal planecontaining the axis of the cylinder bores of its bank, said ports ineach said chamber also being on opposite sides of a transverse planethrough the axis of the cylinder bore of their chamber and normal tosaid first mentioned plane, an intake and an exhaust valve for each saidchamber reciprocably mounted in said heads, said valves being operableto open and close said ports therein, a single rocker shaft mounted oneach said head in a plane extending generally parallel to saidlongitudinal plane, an intake and an exhaust rocker arm for said valvesof each chamber pivotally mounted on said rocker shafts, each of saidrocker arms having opposite lever portions, one of said lever portionsof said exhaust valve rocker arms abutting the stems of said exhaustvalves on one side of their rocker shaft and one of said lever portionsof said intake rocker arms abutting the stems of said intake valves onthe other side of said rocker shaft, a push rod for each of said rockerarms and arranged to abut the other lever portions of said rocker arms,the push rod for each said exhaust valve rocker arm abutting said otherlever portion thereof on one side of its rocker shaft and the push rodfor each said intake valve rocker arm abutting said other lever portionon the opposite side of its rocker shaft, a camshaft rotatably mountedintermediate said banks in said block and extending generally parallelto said longitudinal plane, and said push rods being arranged andconstructed as to operably connect said camshaft at one end and therocker arms to be operated thereby at its other end.

8. In an internal combustion engine having a block provided with acylinder bank having a plurality of cylinder bores longitudinally spacedtherein, a head on said bank having a plurality of combustion chambers,one for each cylinder bore and superimposed thereon, an intake andexhaust system for said combustion chambers of said bank comprising anintake and an exhaust port in said chamber on opposite sides of alongitudinal plane containing the axis of the cylinder bores of saidbank, said ports also being on opposite sides of a transverse planethrough the axis of the cylinder bore of its chamber and normal to saidfirst mentioned plane, an intake and an exhaust valve for each saidchamber reciprocably mounted in said head, said valves being operable toopen and close said ports, a single rocker shaft mounted on said head ina plane extending generally parallel to said longitudinal plane, arocker arm for each of said valves of each chamber pivotally mounted onsaid shaft, each of said rocker arms having opposite lever portions, oneof said lever portions for the exhaust valve rocker arm abutting thestem of said exhaust valve on one side of said rocker shaft and one ofsaid lever portions of the intake rocker arm abutting the stem of theintake valve on the other side of said rocker shaft, a push rod for eachof said rocker arms and arranged to abut the other lever portion of saidrocker arms, the push rod for saidexhaust valve rocker arm abutting saidother lever portion thereof on one side of said rocker shaft and thepush rod for said intake valve rocker arm abutting its said other leverportion on the opposite side of said rocker shaft, a camshaft rotatablymounted in said block and extending generally parallel to saidlongitudinal plane and said push rods being arranged and constructed asto operably connect said camshaft at one end and its rocker arm to beoperated thereby at its other end.

9. In an internal combustion engine having a block with a plurality ofcylinder bores longitudinally spaced therein with their axes in a commonfirst plane, a mounting surface adjacent said cylinder bores, a headmounted on said mounting surface, said head having an equal plurality ofcombustion chambers therein superimposed on said cylinder bores, animproved intake and exhaust system for said combustion chamberscomprising an intake and an exhaust port in each said chamber onopposite sides thereof, the axis of each said exhaust port and the axisof each said cylinder bore being in a second plane offset from saidfirst plane approximately 45, the plane through the axis of each saidintake port and the axis of each said cylinder being offset from saidfirst plane approximately 82 and from said second plane approximatley37, a pair of intake and exhaust valves for each said chamberreciprocably mounted in said head, the axis of said intake valve beingon one side of said common plane and lying in a transverse plane whichis normal to said common plane, and on one side of and in' juxtapositionto a second transverse plane normal to said common plane and through thevertical axis of its cylinder bore, and said intake valve axis beinginclined to said common plane at an acute angle and intersecting saidplane at a point below said mounting surface and the axis of saidexhaust valve substantially paralleling said cylinder bore axis andbeing offset from said common plane and said second transverse plane andon opposite sides of each of these planes from said intake valve axis,said valves being operable to open and close said ports, a single rockershaft mounted on said head parallel to the longitudinal axis thereof, apair of rocker arms for each said pair of valves pivotally mounted onsaid rocker arm, one of said arms of each said pair abutting the stem ofone of said valves of each said pair on one side of said rocker shaft,the other of said arms of each said pair abutting the stem of the otherof said valves of each said pair on the other side of said rocker shaft,a pair of push rods for each said pair of rocker arms, one of said pushrods of each said pair abutting one of said arms of each said pair onone side of said rocker shaft, the other of said push rods of each saidpair abutting the other of said arms of each said pair on the other sideof said rocker shaft, a camshaft rotatably mounted in said blockparallel to the longitudinal axis of said head, said push rodscontacting said camshaft and operative in response to rotation thereofto move said rocker arms and said valves to regulate the fluid flowthrough said ports.

10. In an internal combustion engine having a block with a plurality ofcylinder bores longitudinally spaced therein with their axes in a commonplane, a mounting surface adjacent said cylinder bores, a head mountedon said mounting surface, said head having an equal plurality ofcombustion chambers therein superimposed on said cylinder bores, animproved intake and exhaust system for said combustion chamberscomprising an intake and an exhaust port in each said chamber onopposite sides thereof and offset from said common plane, a pair ofintake and exhaust valves for each said chamber reciprocably mounted insaid head, the axis of said intake valve being on one side of saidcommon plane and lying in a transverse plane which is normal to saidcommon plane, and on one side of and in juxtaposition to a secondtransverse plane normal to said common plane and through the verticalaxis of its cylinder bore, and said intake valve axis being inclined tosaid common plane at an acute angle and intersecting said plane at apoint below said mounting surface and the axis of said exhaust valvesubstantially paralleling said cylinder bore axis and being offset fromsaid common plane and said second transverse plane and on opposite sidesof each of these planes from said intake valve axis, said valves beingoperable to open and close said ports, a single rocker shaft mounted onsaid head parallel to the longitudinal axis thereof, a pair of rockerarms for each said pair of valves pivotally mounted on said rocker arm,one of said arms of each said pair abutting the stem of one of saidvalves of each said pair on one side of said rocker shaft, the other ofsaid arms of each said pair abutting the stem of the other of saidvalves of each said pair on the other side of said rocker shaft, a pairof push rods for each said pair of rocker arms, one of said push rods ofeach said pair abutting one of said arms of each said pair on one sideof said rocker shaft, the other of said push rods of each said pairabutting the other of said arms of each said pair on the other side ofsaid rocker shaft, a camshaft rotatably mounted in said block parallelto the longitudinal axis of said head, said push rods contacting saidcamshaft and operative in response to rotation thereof to move saidrocker arms and said valves to regulate the fluid flow through saidports, all of said rocker arms being substantially the same length, andall of said push rods being substantially the same length.

11. In an internal V type combustion engine, a cylinder block, opposedcylinder banks thereon, a plurality of cylinder bores in each said banklongitudinally spaced along a common plane, a camshaft rotatably mountedin said block parallel to said common plane, a head mounted on each saidbank, each said head having an equal plurality of combustion chamberscoinciding with said cylinder bores of each said bank, an intake and anexhaust valve in each combustion chamber offset on opposite sides ofsaid common plane, a rocker shaft mounted on each said head parallel tosaid common plane thereof and lying in a plane intermediate the stems ofsaid intake and said exhaust valves, a plurality of intake valve rockerarms and exhaust valve rocker arms pivotally mounted on each said rockershaft, said intake valve rocker arms having first portions on one sideof their rocker shaft abutting the stems of their intake valves, saidexhaust valve rocker arms having first portions on the other side oftheir rocker shaft abutting the stems of their exhaust valves, and aplurality of push rods abutting said camshaft and a second portion ofeach said rocker arm lying on the side of their rocker shaft opposite tosaid first portion of each said rocker arm.

References Cited in the file of this patent UNITED STATES PATENTS1,306,949 Coatalen June 17, 1919 1,403,350 Short Jan. 10, 1922 1,488,285Rhoads Mar. 25, 1924 1,698,995 Harrington I an. 15, 1929 2,126,939Winfield Aug. 16, 1938 2,523,611 Clayton Sept. 26, 1950 2,669,227Drinkard 1. Feb. 16, 1954 2,700,969 Nallinger Feb. 1, 1955 2,765,781Turlay Oct. 9, 1956 FOREIGN PATENTS 635,240 Great Britain Apr. 5, 1950968,120 France Apr. 12, 1950 276,820 Switzerland Nov. 1, 1

UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent, N9.2,957,461 October 25, 1960 Melbourne L; Carpentier et al.

It is herebycertified that-error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 12, line I l for "operable" read operably line 65, after "in"insert each Signed and sealed this 2nd day of May 1961 (SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents

